Modifying the shape and color of hair represents an important area of modern cosmetics. The consumer resorts to color-changing agents for fashionable hair style color schemes or for concealing gray or white hair with fashionable or natural color tints.
For the provision of color-changing cosmetic agents, especially for the skin or keratin-containing fibers such as for example human hair, the person skilled in the art is aware of diverse systems according to the requirements of the dyeing or color modification.
The so-called oxidation dyes are used for long-lasting, intensive colorations with corresponding authentic characteristics. Such dyes usually comprise oxidation dye precursors, the “developer components” and “coupler components”. Under the influence of oxidizing agents or from atmospheric oxygen, the developer components form the actual colorants among each other or by coupling with one or more coupler components. The oxidation dyes are distinguished by intensive, outstanding, long-lasting coloration results. However, for colorations with a natural appearance, a mixture of a large number of oxidation dye precursors can be employed; in many cases, further substantive dyes are used for nuancing.
In spite of their advantageous coloration properties, oxidative hair dyeing agents often present disadvantages for the user, such that there is a constant need for further development of oxidation dye precursors.
In the search for oxidation dye precursors with a good tolerability profile, many compounds have been studied but they frequently suffer from application related problems, especially the lack of gray coverage capability. Moreover, in spite of the already highly developed dyeing systems, there still exists the need for dyeing systems that achieve excellent luminance and intensity of the colorations, and that at the same time, however, provide very good durability, very good fastness and an excellent homogeneity.
In particular, there is a need for improvement in the red coloration segment.
Many known dyeing systems, with which red color nuances can be obtained, provide inadequate wash fastness and insufficient leveling power.
In the published application DE 2516117, triaminoalkoxypyrimidine derivatives are proposed as toxicologically and dermatologically harmless developer components in oxidative hair dyes.
However, it was found that the obtained color nuances disclosed in DE 2516117 are not sufficiently numerous for today's requirements (particularly in the red tints). In addition, some of the coupler components cited in the abovementioned published application are suspected of being sensitizing and/or not toxicologically harmless.
Consequently, the object of the present invention is to reduce the abovementioned disadvantages of oxidative hair dyes. The dyes should produce intensive colorations with vivid colors and with a good resistance towards external influences, in particular with good fastness to light and to washing; also the colorations should suffer neither discoloration nor color shifts even after repeated shampooing of the hair. Furthermore, the dyeing should be as unselective as possible, i.e. achieve colorations that are as uniform and homogeneous as possible on differently pre-treated hair. Moreover, the dyes should have a toxicologically advantageous profile.
Another object of the invention is to find suitable toxicologically and dermatologically harmless coupler components for triaminoalkoxypyrimidine derivatives, with which a great number of color nuances—particularly red color nuances—can be obtained, and which exhibit excellent wash fastness and a particularly good leveling power. Finally, it is desirable to achieve as many nuances as possible of the individual color tints.
Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.